This invention relates to a caster or roller for mounting to an article of furniture to provide movement of the article of furniture on a support surface such as a floor, and more particularly to a caster or roller assembly having a locking feature for selectively preventing movement of the article of furniture on the support surface.
A caster or roller is commonly mounted to an article of furniture to enable the article of furniture to be moved on a support surface such as a floor. Typically, the caster or roller includes a wheel or roller member, which engages the support surface and rotates so as to enable movement of the article of furniture on the support surface.
Certain types of casters or rollers include a locking feature for selectively preventing rotation of the wheel or roller member, to selectively prevent movement of the article of furniture on the support surface. Some locking rollers have a lever that is movable between a locking position and a release position. The lever selectively actuates and releases a locking mechanism that is configured to prevent rotation of the wheel or roller member when actuated. Other types of locking mechanisms have a self-locking feature, which prevents rotation of the wheel or roller member when a load is placed on the article of furniture. Self-locking rollers of this type are used when it is desired to automatically prevent movement of the article of furniture at certain times, such as to maintain a chair in position when an occupant is in the seat of the chair, and to allow ease of movement of the article of furniture at all other times, e.g. when the chair is unoccupied.
It is an object of the present invention to provide a self-locking roller assembly for use with an article of furniture such as a chair. Another object of the invention is to provide such a self-locking roller assembly which is well suited for use with an article of furniture having a base that includes a laterally extending base member to which the roller assembly is mounted. Yet another object of the invention is to provide such a self-locking roller assembly which includes a uniquely configured housing having an engagement surface for selectively preventing rotation of the wheel or roller member of the roller assembly. A still further object of the invention is to provide such a self-locking roller assembly which is relatively simple in its components and construction, so as to provide ease of assembly and manufacture, yet which is configured to effectively prevent rotation of the wheel or roller member when a load is placed on the article of furniture.
In accordance with the present invention, a locking roller assembly for use with an article of furniture includes a housing defining an interior within which a wheel or roller member is located. The housing includes an opening through which a lower portion of the wheel extends, for engagement with a support surface such as a floor. The wheel or roller member is mounted to an axle. A movable mounting arrangement is interposed between the housing and the axle, for providing movement of the housing relative to the axle between a raised position and a lowered position. A biasing arrangement is interposed between the housing and the axle, for biasing the housing toward the raised position. The housing includes an engagement surface in vertical alignment with the wheel. When the article of furniture is not loaded, the biasing arrangement maintains housing in the raised position in which the engagement surface is positioned out of engagement with the wheel, so that the wheel is freely rotatable to provide movement of the article of furniture on the support surface. When a load or other downward force is applied to the article of furniture, the housing is moved downwardly relative to the wheel toward the lowered position, against the force of the biasing arrangement. Such downward movement of the housing causes the engagement surface to move into contact with the wheel, to prevent rotation of the wheel and to thereby prevent movement of the article of furniture when the article of furniture is loaded. When the load on the article of furniture is removed, the biasing force of the biasing arrangement functions to move the housing toward the raised position, which moves the engagement surface out of engagement with the wheel. In this manner, the article of furniture can then be freely moved on the support surface as long as the load on the article of furniture is relieved.
The axle is engaged with the housing via a guide arrangement that guides vertical movement of the axle as the housing is moved between the lowered position and the raised position. The axle guide arrangement is preferably in the form of a pair of slots formed in spaced apart walls that at least in part define the housing interior, and which are configured to receive end portions of the axle. The slots are vertically oriented, so that the slots guide vertical movement of the axle as the housing is moved between the lowered and raised positions.
The housing includes a laterally extending passage, which is configured to receive a component of the article of furniture for use in mounting the roller assembly to the article of furniture. The housing includes an end wall that is in line with the laterally extending passage, and which is configured to at least in part define the interior of the housing. The engagement surface is defined by an inner surface of the end wall.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.